im sure i read somewhere about someone giving the waste gate rod like 2 turns and getting suprising amounts (like VERY suprising amounts!) of boost...as with everything slowly slowy and test with care...

For the record I had a new turbo dropped on mine recently and it was 7.5 - 8 lbs out of the box as measured by my calibrated guage mounted T'd off the standard guage....

For the record go and buy a set of carb balancing guages from a motorbike shop..they are cheap (seems the word TURBO adds $ to the price!) and suprisingly accurate!. and they measure -35lbs to +12 lbs..I have a set of 4 and have used them for all sorts of measuring such as:-

turbo boost
crank presure checking
back presure checking down an exhaust under load
air intake presure checking down the intake system

and lots more things I cant think of right now! A guage beats a 'well i think its better' moment..and how else are you going to see if you have +ive presure in the sum at 4000rpm under load!

just a thought!